Analysis of L28/32 Diesel Engine Parts: Abnormal Vibration Phenomena and Causes of Marine Diesel Engines

1. Fault phenomenon

It is normal for Marine diesel engines to generate certain vibrations due to their burst pressure and inertial force during operation. When the working conditions are constant, the magnitude and law of its vibration are also constant.

In case of abnormal vibration, the following phenomena often occur:

(1) The vibration of all parts of the Marine diesel engine has intensified. Especially for components such as high-pressure oil pipes, intercoolers, and speed regulators, the vibration can be seen with the naked eye, but there is a numb feeling when touched by hand.

⑵ Accompanied by abnormal vibrations, there are often strange sounds as well.

2. Cause analysis

(1) Unbalanced work in each cylinder: Unbalanced fuel supply in each cylinder; The fuel supply angles of each cylinder are unbalanced. The compression ratios of each cylinder are unbalanced.

⑵ Unbalanced inertial force: The mass error of the piston connecting rod groups of each cylinder is too large; The dynamic balance error of the crankshaft is too large, or the crankshaft is bent and deformed; The flywheel balance is out of tolerance. The dynamic balance of the turbocharger rotor is out of tolerance, or the impeller is damaged; The assembly position of the balance shaft gear is wrong. The shock absorber failed. The bearing clearance is too large.

⑶ Installation foundation and alignment with working machinery: The installation foundation is weak and has poor rigidity; Insufficient stiffness of the base; The installation screws are loose. The alignment between Marine diesel engines and working machinery is poor.